The CRC motorplate has some small fins to the side presumably to dissapate heat a little better. The ride height adjusters in the IRS left plate fall outside the plate so the adjuster on the left doesn't get supported 100%.
CRC anodised the plates and presumably afterwards milled some small parts again. The milled parts are bare aluminium wich makes a very nice contrast against the collored anodising. Overall it seems there is just a bit more attention to detail and craftmanship involved with the CRC plates.